FINAL ESSAY Flashcards
The maintenance of normal volume and composition of ECF and ICF is vital to life. List and describe 3 homeostatic mechanisms.
- Maintaining homeostatic O2 and CO2 levels in peripheral tissues requires coordination between several systems: • Particularly the respiratory and cardiovascular systems
Fred has chronic emphysema. Blood tests show that his pH is low but almost normal and his bicarb levels are significantly elevated. How can this be? What would urinalysis show for pH?
emphysema is permanent destruction of the lung tissue end result of the condition is that the respiratory system does not expel CO2 adequately. bicarb levels increase to correct this acidity His urine would have a high pH–his body is trying to get rid of acidity urine would show a low (acidic) pH
Identify and describe the populations of cells found in the alveoli and their functional importance.
type I pneumocytes patrolled by alveolar macrophages (dust cells) Alveolar macrophages engulf small particles that reach lungs
type II pneumocytes (septal cells) that produce surfactant
Identify different factors (surface tension, compliance, airway resistance) that influence pulmonary ventilation and explain how they affect it. What is surfactant’s physiological importance?
ST too high: alveoli have too much surfactant and don’t transport oxygen to the capillaries well.
ST too low: alveoli can collapse and will no longer function
compliance too low: stiff lungs resulting in reduced ventilation
compliance too high: weak lung structure resulting in reduced ventilation even with full inhalation
airway resistance: decreased volume of airflow moving in and out of lungs and reduces ventilation
surfactant: lowers surface tension in alveoli, allowing them to expand and therefore respirate more easily
What is Tidal Volume?
the amount of air moving into and out of the lungs during a single respiratory cycle
500mL
What is Inspiratory Reserve Volume (IRV)?
After a normal inspiration
3300 / 1900 mL
What is Expiratory Reserve Volume (ERV)?
After a normal exhalation
1000 / 700 mL
What is Residual Volume?
After maximal exhalation
1200 / 1100 mL
What is Minimal Volume?
30 - 120 mL
What is Inspiratory Capacity?
Tidal Volume + Inspiratory Reserve Volume
What is Functional Residual Capacity (FRC)?
Expiratory reserve volume + residual volume
What is Vital Capacity?
Expiratory reserve volume + tidal volume + inspiratory reserve volume
What is total lung capacity?
Vital capacity + residual volume
6000 / 4200 mL
